Research Of StCen1 And StCdf1/2 Regulating Potato Tuberization

Potato tuberization has been investigated for decades.There are some recent advances have defined some components of photoperiodic signalling that control tuberization.Depend on our previous study in a diploid population 06H1,a TFL1 orthologue named St CEN1 was identified for rapid tuber sprout growth,but later found also affecting tuberization.To investigate its function on controlling tuberization,both the cv.Desirée and S.Andigena transgenic lines were planted and investigated the tuberization phenotype.It is clear that St CEN1 RNAi lines initiated stolons and tubers earlier than wild type while the over-expressing lines later than wild type.And the phenotype was not affected by photoperiod.Based on the expression profile analysis,it is clear that St CEN1 regulates potato tuberization independent of St SP6 A.To investigate the mechanism of St CEN1 regulating tuberization,the photosynthesis rates and sugars in leaves were also analysed and the results indicates they are not affected by St CEN1.Based on the research model of “florigen” in which FT binds FD and promotes flowering and “anti-florigen” with TFL1 binding FD repressing flowering,we raised the hypothesis that St CEN1 and St SP6 A balance tuber initiation by forming the “tuberigen” and “anti-tuberigen” model.So we designed the yeast two hybrid and Bi FC experiments to investigate the interaction of St CEN1 with St FD and St14-3-3 proteins and the results demonstrated the proteins interaction and the mechanism of St CEN1 regulates potato tuberization.In the research of StCDF1/2 regulating potato tuberization,we analysed the expression profiles of St CDF1/2,St CO1/2,St SP5 G,St SP6 A,St PRR5A/B and St PRR7 in 48 h under both long day and short day light.Based on the expression rhythms of St CDF1/2,St CO1/2 and St SP5 G we raised the hypothesis that St CDF1/2 regulates the expression of St SP5 G directly.Based on the promoter analysis of St SP5 G,we found the potential binding sites of St CDF1/2.We also designed the yeast one hybrid and EMSA experiments to test the interaction of St CDF1/2 proteins and St SP5 G promoter.Depend on the expression profiles of St CDF1/2,St PRR5A/B and St PRR7 we raised the potential regulation model of St PRR genes regulate the expression of St CDF genes causing the expression rhythm of St CDF1/2.Those results have important theoretical guiding significance for further understanding of potato tuberization.